*{
    margin:0px;
    padding:0px;
}
body{
    background-image: url("/img/背景2.jpg");
    background-size:100%,100%;
    background-repeat: no-repeat;
}
#main{
    border:1px solid black;
    width:800px;
    height:600px;
    background-color: rgba(44,40,44,.4);
    border-radius: 10px;
    /*设置div块居中*/
    position: absolute;
    left:0;
    top:0;
    right:0;
    bottom: 0;
    margin: auto;
}
#divhead p{
    margin-top:30px;
    text-align:center;
    font-size:30px;
    color:white;
}
#divuser,#divpass,#divsub,#divend,#divimg{
    margin-top:30px;
    text-align:center;
    color:white;
}
div input{
    width:200px;
    border:0px;
    border-bottom:1px solid white;
    background-color:transparent; /* 背景色透明 */
    color:white;
}
div input:focus{
    height:25px;
}
#divsub button{
    border:1px;
    border-radius: 20px;
    width:100px;
    height:25px;
    background-color: azure;
    color:blueviolet;
}
#divend button{
    border:1px;
    border-radius: 20px;
    width:80px;
    height:20px;
    background-color:#6b6b6b;
    color:blueviolet;
}
#divuser,#divpass,#divsub,#divend，#divimg{
     margin-top:30px;
     text-align:center;
     color:white;
 }
div input{
    width:200px;
    border:0px;
    border-bottom:1px solid white;
    background-color:transparent; /* 背景色透明 */
    color:white;
}
div input:focus{
    height:25px;
    outline:none;
}
#divsub input{
    border:1px;
    border-radius: 20px;
    width:100px;
    height:25px;
    background-color: azure;
    color:blueviolet;
}
#toteacher{
    margin-top:30px;
    text-align:center;
    color:white;
}
#divend button{
    border:1px;
    border-radius: 20px;
    width:80px;
    height:20px;
    background-color:#1aa094;
    color:blueviolet;
}
#divimg{
    color:white;
}
